In general, ink jet printing machines or printers include at least one printhead that ejects drops or jets of liquid ink onto a recording or image forming media. A phase change ink jet printer employs phase change inks that are solid at ambient temperature, but transition to a liquid phase at an elevated temperature. The molten ink can then be ejected by a printhead to form an ink image on an image receiving member. The ink image may be formed on a layer of release agent coating an intermediate imaging member, such as a rotating drum or belt, and then the image is transferred to an image receiving substrate, such as a sheet of paper, as the substrate passes through a nip formed between a transfix roller and the intermediate imaging member. In other solid ink printing systems, the ink may be ejected directly onto printing media directed past the printheads.
In various modes of operation, ink may be purged from the printheads to ensure proper operation of the printhead. During purging, ink is typically forced through the ink pathways, chambers, and out the inkjet apertures of the faceplate of the printhead to recover missing or weak inkjet caused by foreign contaminants, air bubbles in the printhead, dried ink, broken ink meniscus around the apertures, ink movement in the printheads during docking and undocking of frame members, and other debris from, in, and around the inkjet ejectors. The purged ink flows down and off the face of the printhead typically to a waste tray positioned below the printhead. Absent any additional structure, the ink can flow freely along the bottom edge of the printhead and drip from the printhead anywhere along the bottom edge. To help control this dripping flow of waste ink, a drip bib may be added near the bottom edge of the printhead.
Previously known drip bibs were formed by generally flat plates that were secured to printheads by fasteners, such as screws or bolts. When secured to the printhead, the upper edge of these previously known drip bibs were generally in contact with the printhead adjacent the lower edge of the ejecting face along the entire drip bib upper edge. Because the previously known drip bibs were secured to the printhead with a plurality of screws, the majority of the clamping force of the fasteners against the drip bib is exerted along the contact edge of the drip bibs in the areas that are closest to the screws with lesser force being applied to the contact edge as the distance from the fasteners along the contact edge increases. This variation in clamping force can cause deformation or distortion of the drip bib, and, consequently, a corresponding distortion of the printhead. Distortion or deformation of a printhead may cause some areas of the printhead to be closer or farther away from the imaging member than others during printing which, in turn, may adversely impact the print quality of images formed by the printhead.